A student writes the following expression for the equilibrium NH _4 HS (s) NH _3(g) +…

CHEMISTRY · Single correct · A Level · Chemistry · Gaseous equilibria (Kp) · Gaseous equilibria (Kp)

Problem

A student writes the following expression for the equilibrium

\text{NH}_4\text{HS}(s) \rightleftharpoons \text{NH}_3(g) + \text{H}_2\text{S}(g)

K_p = \dfrac{(P_{\text{NH}_3})(P_{\text{H}_2\text{S}})}{P_{\text{NH}_4\text{HS}}}

". Which revision most accurately reflects the correct form of

K_p

for this reaction? (a)

K_p = \dfrac{(P_{\text{NH}_3})(P_{\text{H}_2\text{S}})}{P_{\text{NH}_4\text{HS}}}

(b)

K_p = (P_{\text{NH}_3})^2(P_{\text{H}_2\text{S}})^2

(c)

K_p = (P_{\text{NH}_3})(P_{\text{H}_2\text{S}})

(d)

K_p = (P_{\text{NH}_3})^2